Last modified: June 2019

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/plot_marx_spectrum.html
AHELP for CIAO 4.15 Sherpa

plot_marx_spectrum

Context: contrib

Synopsis

Plot up the model spectrum in the form required by MARX

Syntax

plot_marx_spectrum(id=None, elow=None, ehigh=None, ewidth=None,
norm=None)

Description

The plot_marx_spectrum() command creates a plot of the current model values in the form expected by MARX (the Chandra simulator).

Loading the routine

The routine can be loaded into Sherpa by saying:

from sherpa_contrib.marx import *

Arguments

Name Default value Description
id None Which dataset to use: if None then the value returned by get_default_id() will be used.
elow None The minimum energy at which to evaluate the model; this parameter controls the lower edge of the lowest-energy bin, and is in keV. A value of None means to use the lowest energy bin from the ARF grid. This value should not be smaller than 0.2 keV.
ehigh None The maximum energy at which to evaluate the model; this parameter controls the upper edge of the highest-energy bin, and is in keV. A value of None means to use the highest energy bin from the ARF grid. This valus should not be larger than 10 keV.
ewidth None The bin width to use, in keV. A value of None means to use the bin width from the ARF grid.
norm None A scaling factor to allow you to easily change the overall flux of the model. A value of None is equivalent to a factor of 1; a value of 10 would create a MARX spectral model ten times brighter than the input model.
overplot False If True then the data is added to the current plot, otherwise a new plot is created.
clearwindow True If True then clear out the current plot area of all existing plots. This is not used if overplot is set.

Examples

Example 1

sherpa> plot_marx_spectrum()

Create a plot of the model for the default dataset using the units expected by MARX.

Example 2

sherpa> plot_marx_spectrum(elow=1, ehigh=8)

In this example the plot is restricted to the range 1 to 8 keV, using the default binning given by the ARF grid. Note that this energy range need not overlap the range used to fit the data (or even the energy ranges of the ARF and RMF files). It should however remain within the range 0.2 to 10 keV.


Changes in the scripts 4.11.4 (2019) release

Plotting can now use matplotlib

The plot_marx_spectrum() routine now uses the Sherpa plot backend (controlled by the plot_pkg setting in a user's ~/.sherpa.rc file), rather than always using ChIPS. The Y axis now displays the units required by MARX - namely photon/cm^2/s/keV - rather than photon/cm^2/s. As part of this update the extra labelling in the plot - that gave the model name and dataset identifier - have been removed (although the model name is now included in the plot title).

Optional arguments

The overplot and clearwindow optional arguments have been added to plot_marx_spectrum.


Bugs

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

See Also

contrib
get_data_prof, get_data_prof_prefs, get_delchi_prof, get_delchi_prof_prefs, get_fit_prof, get_marx_spectrum, get_model_prof, get_model_prof_prefs, get_resid_prof, get_resid_prof_prefs, get_source_prof, get_source_prof_prefs, plot_chart_spectrum, prof_data, prof_delchi, prof_fit, prof_fit_delchi, prof_fit_resid, prof_model, prof_resid, prof_source, save_marx_spectrum, sherpa_marx
data
get_arf_plot, get_bkg_chisqr_plot, get_bkg_delchi_plot, get_bkg_fit_plot, get_bkg_model_plot, get_bkg_plot, get_bkg_ratio_plot, get_bkg_resid_plot, get_bkg_source_plot
modeling
normal_sample, t_sample, uniform_sample
plotting
get_cdf_plot, get_energy_flux_hist, get_pdf_plot, get_photon_flux_hist, get_pvalue_plot, get_pvalue_results, get_split_plot, plot, plot_arf, plot_bkg, plot_bkg_chisqr, plot_bkg_delchi, plot_bkg_fit, plot_bkg_fit_delchi, plot_bkg_fit_resid, plot_bkg_model, plot_bkg_ratio, plot_bkg_resid, plot_bkg_source, plot_cdf, plot_chisqr, plot_data, plot_delchi, plot_energy_flux, plot_fit, plot_fit_delchi, plot_fit_resid, plot_model, plot_model_component, plot_order, plot_pdf, plot_photon_flux, plot_pvalue, plot_ratio, plot_resid, plot_scatter, plot_source, plot_source_component, plot_trace, set_xlinear, set_xlog, set_ylinear, set_ylog
psfs
plot_kernel
statistics
get_chisqr_plot, get_delchi_plot
visualization
contour_resid